[solved] ECU taking a crap? - nope - it's the fuel pump

[KSpecII]

hi all,

just ran into some problems just now when out on a ride with my friends.

long story short..

bike sputters and stalls intermittently with no FI error codes..

tried removing the PC2 i had and still the same...

able to crank but no sparking... would come on and off...

running 13.1 1397 kit


any ideas what the prob may be?

HELP.. (also the ECU feels a bit warm.. i suspect is an internal short circuit <- is it possible?)
What can i do to diagnose?

thanks in advance

[KSpecII]

just to add.. the prob only seems to appear when the engine is hot... (but don't know if it's really the cause..)

I'm really leaning towards a dying ECU...

[ZX-ALAN]

Check the tip over sensor, we had this problem last weekend on a group ride....FI light would come on, bike would just die, then start back up, run a while, hit the gas and it would die...The bracket for the tip over sensor was broke and the sensor was just laying there.

If not that, swap ECUs with a buddy with the same year bike just to try it.

[ZX-ALAN]

Oh shit, I just read its a hot problem.....not likely the tip over... I doubt its the ECU then if its a hot problem.  I would check the crank sensor gap first.

[KSpecII]

Oh shit, I just read its a hot problem.....not likely the tip over... I doubt its the ECU then if its a hot problem.  I would check the crank sensor gap first.

are you referring to the crankshaft position sensor at the rotor there? but the prob is that i'm not getting any FI errors..

[BATTMAN]

I had a bad ECU just recently.  It tripped the FI code though.  I still didnt know it was the ecu though.  They are very reliable.  Just swap one out with your buddy to see if you still have the problem.  If you dont know anyone with a busa, just go to the dealership and have them pull one off a new bike to check it( depending on what year your bike is)

[KSpecII]

I had a bad ECU just recently.  It tripped the FI code though.  I still didnt know it was the ecu though.  They are very reliable.  Just swap one out with your buddy to see if you still have the problem.  If you dont know anyone with a busa, just go to the dealership and have them pull one off a new bike to check it( depending on what year your bike is)

ya.. that's what i intend to do. i happen to have a spare ecu lying around with my mechanic. shall go swap it out and see if it solves the problem...

i'm just trying to narrow down if there are other possible causes...

what about a faulty PC2? what are the symptoms? any way to check?
actually i'm wondering if i can crank up the 1397 motor alone on the stock ecu...

[ZX-ALAN]

Yeah your 1397 will start up and run fine without the PCII...I mean I wouldn't ride it but just to start it, it will be ok.  PCIIs and especially PCIIIUSBs are all piece of shit.  I have had all of them fail. They all do something different when they start to fuck up.  They usually don't just crap out totally, they will make the bike start doing some screwy stuff.  I had way more problems with the USBs then the IIs.  Matter in fact, I have an OLD pcii I have held on to because it always works well and has never fucked up...You can try it out if you like, I KNOW it works well.  BUT you said the problem exists with the PCII disconnected so....NO FI lights huh???HMMMM let me think about it a while.

Have you checked the adjustment on the TPS out of curiousity, sometimes thats makes them do weird shit to when it gets off.

[BATTMAN]

If it's no FI light, it probbly isnt the ecu( it could be though)  Check to see if your kickstand sensor is tight.  Also check your tipover sensor.  What year is your bike?  Check the screen on the fuel filter also.

[ZX-ALAN]

He says its not running due to lack of firing the plugs, so that would eliminate the TPS.  I would then check the kickstand switch, engine kill switch, clutch switch, tip over switch, crank position sensor(air gap) then swap the ECU.....

Or you could swap the ECU first as its the easiest. Not a lot of stuff controls the ignition(unlike the fuel) but I would think you would get a code for coils not firing etc...maybe not if its a safety device though..HMMM

[BATTMAN]

He says its not running due to lack of firing the plugs, so that would eliminate the TPS.  I would then check the kickstand switch, engine kill switch, clutch switch, tip over switch, crank position sensor(air gap) then swap the ECU.....

Or you could swap the ECU first as its the easiest. Not a lot of stuff controls the ignition(unlike the fuel) but I would think you would get a code for coils not firing etc...maybe not if its a safety device though..HMMM

Just what he said

[Jebakaturbogsxrpilot]

  Have you checked the fuel system, are you sure there is no spark? Look for kinked fuel lines, collapsed lines. What year busa, could be fuel screens.

[KSpecII]

mine's a 99.. in fact, i've juz recently done an overhaul, i removed the fuel screens on the injectors and changed the fuel pump filter already...

gonna check the switches and the fuel lines first... next will be the ECU..

just wondering how the air gap of the crank position sensor will affect the running of the bike...

[Jebakaturbogsxrpilot]

mine's a 99.. in fact, i've juz recently done an overhaul, i removed the fuel screens on the injectors and changed the fuel pump filter already...

gonna check the switches and the fuel lines first... next will be the ECU..

Make sure you try and figure out if it is a fuel problem or spark problem, as they both have simillar symptoms. Although If the bike is dying or stalling intermittently it sounds more like fuel to me. You may have to put and inline fuel gauge in temporariuly to keep an eye on which one it really is.

[KSpecII]

ecu has been swapped.. it's not it...

seems like a fuelling problem... adjusted the fuel lines slightly...
cleaned the contacts of the fuel pump..
seems to be running ok so far...

shall carry on monitoring...

shall let you guys know if i discover anything...

thanks for the help so far!

[KSpecII]

tried it out again just now.. the engine will still sputter and its not as serious as before. I wonder wat i did rite...

somehow the feeling at low end seems quite reach... but at occasionally it'll run real smooth and fine...

hmmm.. really dunno what's happening...

[Pinky]

sounds like fuel lines
have a 99 motor do that to me till i put very firm fuel lines on it then it ran great

[mike46]

sounds like fuel lines
have a 99 motor do that to me till i put very firm fuel lines on it then it ran great

What line did you use?

[badassblackbusa]

check the plug to the fuel pump. just fixed one of those a few weeks ago same symptoms. plug would get loose and overheat when engine was hot.

[KSpecII]

check the plug to the fuel pump. just fixed one of those a few weeks ago same symptoms. plug would get loose and overheat when engine was hot.

is that the electrical plug u are referring to?

[badassblackbusa]

yep.

[Pinky]

sounds like fuel lines
have a 99 motor do that to me till i put very firm fuel lines on it then it ran great

What line did you use?

aeroquip and good year
started out with som e cheepie line but it was junk (this was a 99 in 04 bike with 99 tank and pump to get running for while)
the aeroquip i used is the blue line

[Jebakaturbogsxrpilot]

sounds like fuel lines
have a 99 motor do that to me till i put very firm fuel lines on it then it ran great

What line did you use?

aeroquip and good year
started out with som e cheepie line but it was junk (this was a 99 in 04 bike with 99 tank and pump to get running for while)
the aeroquip i used is the blue line

Aeroquip is some good stuff, however kind of expensive, you get what you pay for. I used the gates fuel injection line from napa, about $6 a foot! Very firm stuff and you can bend it in a nice radius without kinking

[Pinky]

sounds like fuel lines
have a 99 motor do that to me till i put very firm fuel lines on it then it ran great

What line did you use?

aeroquip and good year
started out with som e cheepie line but it was junk (this was a 99 in 04 bike with 99 tank and pump to get running for while)
the aeroquip i used is the blue line

Aeroquip is some good stuff, however kind of expensive, you get what you pay for. I used the gates fuel injection line from napa, about $6 a foot! Very firm stuff and you can bend it in a nice radius without kinking

i can get aeroquip for $3-4 a foot if i remember right
its cheeper then the goodyear stuff i got at the auto store

[mike46]

sounds like fuel lines
have a 99 motor do that to me till i put very firm fuel lines on it then it ran great

What line did you use?

aeroquip and good year
started out with som e cheepie line but it was junk (this was a 99 in 04 bike with 99 tank and pump to get running for while)
the aeroquip i used is the blue line

Thanks. I've used just about every Earl's line but their quality has really taken a dive IMO since Holley bought them out. The oil coolers have been very disappointing over the past several years.